GazeTK

/*

 * Copyright 2015 Thies Pfeiffer and Dimitri Heil

 * GazeTk is distributed under the terms of the GNU General Public License

 * 

 * This file is part of GazeTk.

 * 

 * GazeTk is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, either version 3 of the License, or

 * (at your option) any later version.

 * 

 * GazeTk is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

 * GNU General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with GazeTk. If not, see <http://www.gnu.org/licenses/>.

 */

var net = require('net');

var ws = require("nodejs-websocket");

var HOST = '127.0.0.1';

var PORT = 6555;

var connected = false;

var client = new net.Socket();

var connectionManager = [];

var connectionId = 0;

var websocket_server = null;

var eyeTracker = "";

if (process.argv.length == 2) {

        console.log("Start the server with --tracker=smi or --tracker=mygaze or --tracker=eyetribe");

        process.exit();

} else if (process.argv.length > 2) {

        process.argv.forEach(function(val, index, array) {

                if (val.indexOf("tracker") > -1) {

                        eyeTracker = val.split("=")[1];

                }

        });

}

if (eyeTracker == "" || eyeTracker == undefined) {

        console.log("tracker was not set - exiting.");

        process.exit();

}

console.log("Tracker is " + eyeTracker);

function createServer() {

        websocket_server = ws.createServer(function(conn) {

                conn.on("text", function(str) {

                        var senderID;

                        for (var c in connectionManager) {

                                //console.log(c+"{__}"+position);

                                if (conn == connectionManager[c].conn) {

                                        senderID = connectionManager[c].id;

                                }

                        }

                        console.log("Message from connection with id:" + senderID + " : \"" + str + "\"");

                        if (str.indexOf("TYPE") > -1) {

                                console.log("typestring: " + str);

                                var clientType = str.split(':');

                                //connectionManager[connectionId] = new Array();

                                console.log("type = " + clientType[1]);

                                for (var c in connectionManager) {

                                        //console.log("Sending SMI Data: "+str);

                                        if (connectionManager[c]['conn'] == conn) {

                                                connectionManager[c]['type'] = clientType[1];

                                        }

                                }

                        }

                        if (eyeTracker == "smi") {

                                try {

                                        for (var c in connectionManager) {

                                                console.log("Sending SMI Data: " + str);

                                                if (connectionManager[c]['type'] == "browser") {

                                                        connectionManager[c]['conn'].sendText(str);

                                                }

                                        }

                                } catch (err) {

                                        console.log("error in websocketserver: ");

                                        console.log("error at line:" + err.lineNumber);

                                        console.log("error:" + err);

                                        console.log("error at message:" + data);

                                        console.log("trying to establish new connection");

                                        createServer();

                                }

                        }

                        if (eyeTracker == "mygaze") {

                                try {

                                        for (var c in connectionManager) {

                                                console.log("Sending myGaze Data: " + str);

                                                if (connectionManager[c]['type'] == "browser") {

                                                        connectionManager[c]['conn'].sendText(str);

                                                }

                                        }

                                } catch (err) {

                                        console.log("error in websocketserver: ");

                                        console.log("error at line:" + err.lineNumber);

                                        console.log("error:" + err);

                                        console.log("error at message:" + data);

                                        console.log("trying to establish new connection");

                                        createServer();

                                }

                        }

                        if (eyeTracker == "eyetribe") {

                                //send the message from the browser directly to the eyetracker

                                client.write(str);

                        }

                });

                        conn.on('error', function(er) {

  // The error won't crash the process, but what it does is worse!

  // Though we've prevented abrupt process restarting, we are leaking

  // resources like crazy if this ever happens.

  // This is no better than process.on('uncaughtException')!

  console.log(eyeTracker +" disconnected. ERRORMESSAGE: ", er.message);

});

                conn.on("close", function(code, reason) {

                        for (var c in connectionManager) {

                                //console.log(c+"{__}"+position);

                                if (conn == connectionManager[c].conn) {

                                        console.log("connection '" + c + "' disconnected.");

                                        delete connectionManager[c];

                                }

                        }

                });

        }).listen(6777);

        websocket_server.on("connection", function(conn) {

                connectionManager[connectionId] = [];

                connectionManager[connectionId].conn = conn;

                connectionManager[connectionId].id = connectionId;

                console.log("A new client connected with id: " + connectionId);

                connectionId++;

        });

}

if (eyeTracker == "eyetribe") {

        //Heartbeat timer

        setInterval(function() {

                if (connected) {

                        sendHeartbeat(client);

                }

        }, 250);

        client.connect(PORT, HOST, function() {

                console.log('Websocket connected successfully to tcp server(EyeTracker): ' + HOST + ':' + PORT);

                connected = true;

                //check the eyetracker status

                //client.write('{"category": "tracker","request": "get","values": ["push", "iscalibrated" ]}');

                //client.write('{"category": "tracker","request": "set","values": {"push": true,"version": 1}}');

                //client.write('{"category": "tracker","request" : "get","values": [ "push", "iscalibrated" ]}');

        });

} else if (eyeTracker == "smi") {

        console.log('Waiting for messages from SMI EyeTracker on 127.0.0.1:6777');

} else if (eyeTracker == "mygaze") {

        console.log('Waiting for messages from myGaze EyeTracker on 127.0.0.1:6777');

}

//as soon as the websocket receives any data from the eyetracker it is forwarded to the browser

client.on('data', function(data) {

        try {

                for (var c in connectionManager) {

                        console.log("Sending EyeTrackingData to Browser: "+data);

                        connectionManager[c]['conn'].sendText(data);

                }

        } catch (err) {

                console.log("error in websocketserver: ");

                console.log("error at line:" + err.lineNumber);

                console.log("error:" + err);

                console.log("error at message:" + data);

                console.log("trying to establish new connection");

                createServer();

        }

        // Close the client socket completely

        //client.destroy();    

});

// Add a 'close' event handler for the client socket

client.on('close', function() {

        connected = false;

        console.log('EyeTracker Disconnected.');

        createServer();

});

function sendHeartbeat(socket) {

        socket.write("{\"category\":\"heartbeat\",\"request\":null}");

        //console.log('Heartbeat sent.');        

}

try {

        createServer();

} catch (err) {

        console.log("error in websocketserver: ");

        console.log("error at line:" + err.lineNumber);

        console.log("error:" + err);

        console.log("error at message:" + data);

        console.log("trying to establish new connection");

        createServer();

}